Yes, Underground Printing is a legitimate business. It has an average rating of 4.7 from 256 reviews. The company offers screen printing, digital printing, and embroidery on a variety of apparel and promotional products. It has been featured in numerous publications and has been listed on Inc. Magazine's list of fastest-growing companies multiple times. Corporate giants like Google, Amazon, and Target trust Underground Printing for their needs. However, it's always a good idea to check the official Underground Printing website or other review websites for the most current information.